Wyniki wyszukiwania - AGRO

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Wplyw zrywki drewna na degradacje gorskich gleb lesnych

100%

Maciaszek W., Zwydak M.

Zeszyty Naukowe Akademii Rolniczej w Krakowie. Leśnictwo

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1992

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tom 22

29-44

2

Terminologiczne i metodologiczne problemy związane z procesem pozyskiwania i zrywki drewna. Czyli kłopoty z właściwym określaniem i rozumieniem pojęć

100%

Kusiak W., Grodecki J.

Przegląd Leśniczy

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2012

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tom 22

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nr 04

3

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Linowe dźwigi zrywkowe w leśnictwie

88%

Gil W.

Sylwan

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1988

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tom 132

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nr 07

4

Niekonwencjonalne systemy linowe

88%

Stollmann V., Belanova K.

Prace Komisji Nauk Rolniczych, Leśnych i Weterynaryjnych. Polska Akademia Umiejętności

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2007

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tom 09

5

Problem wyboru środków do operacji pozyskaniowo-zrywkowych

88%

Gil W.

Sylwan

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1999

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tom 143

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nr 06

47-56

6

Optymalizacja sposobow realizacji procesu technologicznego pozyskiwania i zrywki drewna na okreslonym obszarze lesnym

88%

Jablonski K.

Rozprawy Naukowe. Akademia Rolnicza im. Augusta Cieszkowskiego w Poznaniu

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2006

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nr 378

1-88

7

Czasochłonność zrywki drewna wyciągarkami zagregowanymi z pilarkami spalinowymi w drzewostanach trzebieżowych

88%

Szewczyk G.

Sylwan

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2011

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tom 155

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nr 06

8

Zrywka drewna ciągnikami forwarder w ujęciu kodeksu praktyk pozyskaniowych

88%

Gil W.

Sylwan

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1999

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tom 143

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nr 07

69-79

9

Jak efektywnie uzytkowac forwardery? Czesc II. Czynniki majace wplyw na efekty pracy

88%

Wiesik J.

Przegląd Techniki Rolniczej i Leśnej

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1998

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nr 11

19-21

10

Wplyw zrywki na spojnosc gleby na szlakach zrywkowych

88%

Checinski P., Hryciuk P., Maciejewski W., Wolkowicz A.

Przegląd Leśniczy

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1996

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tom 06

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nr 07-08

22-23

11

Szlaki zrywkowe w procesie pozyskiwania drewna Cz I. Definicje i znaczenie

88%

Laurow Z.

Przegląd Techniki Rolniczej i Leśnej

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1996

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nr 05

17-18

12

Analiza wydajnosci zrywki drewna w drzewostanach bukowych

88%

Sieniawski W.

Sylwan

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2009

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tom 153

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nr 07

466-471

13

Nowe techniki zrywki linowej

88%

Leszczynski N., Wegrzyn A.

Technika Rolnicza Ogrodnicza Leśna

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2013

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nr 3

14

Mozliwosci zrywki drewna dlugiego i krotkiego za pomoca ciagnikow uniwersalnych

88%

Wiesik J.

Las Polski

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1995

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nr 09

11-12

15

Zasady proekologicznej zrywki drewna w warunkach gospodarki lesnej w gorach

88%

Sosnowski J.

Sylwan

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2003

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tom 147

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nr 05

58-64

16

Zrywka drewna lesnymi kolejkami linowymi

88%

Gornowicz R., Grodecki J., Mokrzycki J.

Przegląd Leśniczy

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2000

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tom 10

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nr 10

4-5

17

Ćwierć wieku na LKT

88%

Grabowska K.

Nowa Gazeta Leśna. Miesięcznik Wszystkich Pracujących w Lesie

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2013

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nr 01

18

Optymalizacja zrywki drewna według kryterium minimalizacji pracy transportowej

75%

Jablonski K., Stempski W.

Sylwan

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2015

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tom 159

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nr 07

The objective of the study was to optimize wood extraction from a clear−cut area to several upper landings located at roads suited for wood haulage in a situation where the room for storing the wood was limited. The optimization process was to divide the clear−cut area into zones, from which the wood assortments should be transported to the different landings, so that the total transportation labour would be minimized. The research was conducted in Oborniki Forest District (western Poland) on a clear−cut area where the harvest of 2027 m3 of wood in four assortments was planned. The optimization method used presented a linear programming problem, which was formulated and solved with the Solver tool, available with a common spreadsheet. The clear−cut area was divided into a number of elementary plots, for which the quantities of the wood to be extracted and distances to the specified landings were determined. Altogether 189 such plots were defined, mostly square in shape and with 20 m long side. Three upper landings for each wood assortment, located at roads accessible to long−distance vehicles were also determined (fig. 1). The minimization of the transport labour needed for the extraction of different wood assortments was set as the criterion for the objective function. The results of the calculations, after putting them on the forest clear−cut area map (fig. 2), provided information about parts of the clear−cut area to which the wood should be extracted to. As it was expected, in the majority of cases, the model directed the wood to the landings, which were the closest, but in case of one assortment, the wood was directed to the landing located a bit further away than to the closest one. The model enabled to minimize the transportation labour spent on wood extraction from the clear−cut area. The calculations did not require any specific applications, enabling users of commonly available spreadsheets, equipped with a Solver tool to perform such calculations.

19

Dokładność określania struktury dnia roboczego metodą obserwacji migawkowych przy zrywce drewna

75%

Pszenny D., Giedrowicz A., Staniszewski P., Moskalik T.

Sylwan

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2019

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tom 163

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nr 04

One of the most difficult technological operations in forest utilization is wood transport, especially its first stage i.e. extraction. This is related to the fact that the forest operations must be economically effective, but also safe for the forest environment. Difficult terrain conditions require determining and choosing the optimal variant of skidding. The most popular method for optimizing work is the use of working day photography. However, it is time−consuming and labor−intensive, that is why it is possible to use an alternative way of measuring working time, i.e. snapshot observations. It is therefore important to determine which measurement method is appropriate for the complicated and variable production processes in forestry. The aim of the research was to assess the accuracy of snapshots at intervals of 1 and 5 minute in relation to the stopwatch time study (which was a reference measurement), carried out for a two−stage wood logging in quasi−mountain terrain conditions of the Elbląg Upland (N Poland). It’s mountain like characteristics causes some difficulties in the forest works. Data for the study were collected in two periods – summer and winter. We did not prove statistically significant differences between the methods studied.

20

Wydajność zrywki drewna skiderem na terenach pochyłych

75%

Kulak D., Stanczykiewicz A., Szewczyk G., Wala L.

Sylwan

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2019

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tom 163

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nr 07

The aim of the study is to characterise the working time structure of an operator of the LKT 82 skidder performing timber skidding on the sloping area, and to develop models of efficiency and time−consumption of the work depending on selected factors characteristic of the described transport process. The research was performed in the Sucha Forest District (S Poland). We considered two treatments: late thinning and felling performed in stands with the dominating share of beech. Logs obtained with chainsaws were initially extracted with horses and laid at the slope road. Later on the additional skidding with skidder tractor was done. Continuous timing of individual operations was performed with the use of a microcomputer equipped with time measurement software (accuracy of 1 second). We also determined skidding distance using a GPS device, the number of extracted logs in the load, and the volume of the logs. The total timing measurements lasted for a total of 70 h 24 min 27 s. During that time, the tractor made 72 cycles, transporting 998 logs with a total volume of 493.3 m³. In the mature stand, the average skidding distance amounted to approximately 1,160 m, a single load consisted of 3−4 logs with a volume of 7.7 m³. The operational efficiency of the skidding was 9.1 m³/h. In the thinning stand, the skidding distance was 1,230 m, the average load consisted of 22 logs with a volume of 5.8 m³. The operational efficiency amounted to 7.8 m³/h, on average. The working time structure was dominated by auxiliary (over 60%) and effective (nearly 30%) times. The obtained regression models of the duration of activities from the group of operational times were characterised by high correlation coefficient (about 0.75 for skidding time and driving without a load). Relatively strong relationships (r > 0.5) were also found between the times of collecting cable pulling and load attachment, and the volume of the extracted loads, and in the case of the times of collecting cable pulling also the type of treatment performed. The regression models for the times of log stacking, pulling the loads up with the winch and detaching them, despite the fact that they were statistically significant, characterised by relatively low correlation coefficients. The relationship between skidding efficiency and skidding distance was also determined (fig.). The duration of skidding cycles was described using the multiple regression with the volume of single loads and the skidding distance as the determinants. The regression models of skidding efficiency and time−consumption of skidding cycles may find practical application in estimating the efficiency of the tasks performed in stands and under conditions similar to those analysed in the present research.

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